Wideband bandstop filter with sub-harmonic stubs

摘要

The performance of a wideband bandstop transmission line filter employing a series overlay inductor over two stubs resonating at respectively one half and one quarter of the centre frequency, is described. The structure contributes seven transmission zeros to the stopband and the performance compares to that of a Cauer filter. The structure has the advantage of having impedance levels that are readily realizable.